The present invention is directed to an electrical load output level control network and, more particularly, to a novel passive network for controlling the output level of a load, such as a ballast-lamp lighting load combination.
The ability to control the output level of a load, particularly from a remote location, facilitates many economic advantages in this day and age of energy conservation. With the advent of variable load-output-level controls, such as are found in the variable-output gas-discharge lamp/ballast system of co-pending U.S. patent application Ser. No. 117,942, filed on Aug. 14, 1980, assigned to the assignee of the present application and incorporated herein by reference, control of fluorescent lamp light output is now practical. However, greatest acceptance of variable output level control systems, particularly those of the type requiring the use of a variable impedance connected to the load controller input for establishing the load output level, require that an efficient, low-cost and highly reliable variable impedance network be provided. It is also highly desirable that the control network be entirely passive and provide isolation between the user (adjusting the control network) and the potentially hazardous voltages and current utilized in the load device.